The utility model relates to the field of the vacuum sealing machine, in particular to a cavity-type vacuum sealing machine with small volume and low cost.
The vacuum sealing machine finishes the sealing procedure by putting food into a packaging bag and pumping air out of the packaging bag to achieve the predetermined vacuum degree. The vacuum sealing machine can have the following functions of vacuumizing and sealing the bag or directly sealing the mouth of the bag. The prior vacuum sealing machine is generally divided into two types; one is a direct-pump type incapable of packaging products containing high liquid and the other is a cavity type capable of packaging products containing high liquid or pure liquid products. However, the prior cavity-type vacuum sealing machine is only used in the large production occasions such as factories; and the vacuum sealing machine utilizes a large vacuum pump, has the disadvantages of complex structure, high cost and large volume and is not suitable for household use. The prior small vacuum sealing machine for household use is just the direct pump type, which is incapable of packaging products containing high liquid or pure liquid products and does not meet the household requirements of packaging products containing high liquid or pure liquid products.
The prior household vacuum sealing machine has smaller volume and generally employs a small vacuum pump; the vacuum pump utilizes a direct-current motor and has one suction port and one exhaust port; the vacuum pump has slow pumping speed and low pumping pressure, which results in lower pumping efficiency and may result in too much air remained in the packaging bag, so that the shelf life of food in the packaging bag cannot be guaranteed. Two pumps are also utilized; two pumps in the dual-pump structure can only be connected in series or in parallel; the pumping speed cannot be accelerated when the vacuum pressure is boosted or the vacuum pressure cannot be boosted when the pumping speed is accelerated. In addition, the current occasions such as factories generally utilize the large vacuum sealing machine, which utilizes a large vacuum pump or a rotary-vane vacuum pump and uses a large alternating current motor; although the vacuum pump has high pumping speed and high pumping pressure, it has large volume and high cost and is not suitable for families and small sites.